4,410 research outputs found

    Persistence of the Jahn–Teller distortion of Mo5+ in double perovskites : a structural study of Ba2NdMoO6 and the effect of chemical doping in Ba2Nd1xYxMoO6

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    The cation ordered perovskites Ba2NdMoO6 and Ba2Nd1-xYxMoO6 have been structurally characterised by a combination of neutron and X-ray powder diffraction. Ba2NdMoO6 retains the tetragonal room temperature structure on cooling to 150 K[: I4/m; a = 5.98555(5)Å, c = 8.59510(10) Å] although the MoO6 octahedra distort with an elongation of two, trans Mo-O bonds. Neutron diffraction data collected at T ≀ 130 K show that this compound has undergone a structural distortion to a triclinic space group, although the MoO6 octahedra do not distort any further on cooling below this temperature [at 130 K: ; 5.97625(14) Å, 5.9804(2) Å, 8.59650(13) Å, 89.876(2) °, 89.921(3) °, 89.994(2) °]. The room temperature tetragonal space group symmetry of Ba2NdMoO6 is preserved in the series Ba2Nd1-xYxMoO6 up to composition 0.35 ≀x< 0.5. The lattice parameters converge as the value of x increases until cubic symmetry is reached for the composition for Ba2Nd0.5Y0.5MoO6 [ ;a = 8.4529(3) Å]. Magnetic susceptibility measurements show that all of these compounds display the Curie-Weiss behaviour associated with a fully localised electronic systems. The paramagnetic moments show good agreement with those anticipated to arise from the spin-only contribution from Mo5+ (S=1/2, ”so = 1.73 ”B) and the moment of 3.62 ”B associated with the spin-orbit coupling of the 4I9/2 ground state of Nd3+. For x≀0.125 this series shows a magnetic transition in the range 10 to 15 K indicative of a distortion of the MoO6 octahedra in these compounds that is similar to Ba2NdMoO6

    End-user informed demographic projections for Hamilton up to 2041

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    This report provides a set of projections of the population of Hamilton City and the larger Hamilton Zone. The projections have been calculated by means of the cohort component model. The projections can be considered alongside official Statistics New Zealand projections, but differ from the latter in terms of assumptions made about net migration. These assumptions constitute a number of scenarios that were informed by the Hamilton City Council and local consultations. These scenarios are linked to the potential impact of a number of economic development activities. The report also contains projections of the number of households, the labour force and two ethnic groups: Māori and New Zealand Europeans. In addition, a dwellings-based methodology is used to produce small area (Census Area Unit) projections. Across the scenarios, Hamilton City’s projected population growth over the next two decades ranges from 13.8 percent to 36.0 percent. This is between 1.5 to 12.2 percentage points higher than the corresponding projected national growth

    In-situ absorption and fluorescence studies of electrogenerated species

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    Imperial Users onl

    Economic significance of trade associations

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    This item was digitized by the Internet Archive

    Study of the spectroscopy and collision dynamics of SiX (X=F,Cl) radicals

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    Washington Case Law-1954; Agency

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    Covers cases on presumption as to scope of employment

    Empirical and Statistical Application Modeling Using on -Chip Performance Monitors.

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    To analyze the performance of applications and architectures, both programmers and architects desire formal methods to explain anomalous behavior. To this end, we present various methods that utilize non-intrusive, performance-monitoring hardware only recently available on microprocessors to provide further explanations of observed behavior. All the methods attempt to characterize and explain the instruction-level parallelism achieved by codes on different architectures. We also present a prototype tool automating the analysis process to exploit the advantages of the empirical and statistical methods proposed. The empirical, statistical and hybrid methods are discussed and explained with case study results provided. The given methods further the wealth of tools available to programmer\u27s and architects for generally understanding the performance of scientific applications. Specifically, the models and tools presented provide new methods for evaluating and categorizing application performance. The empirical memory model serves to quantify the hierarchical memory performance of applications by inferring the incurred latencies of codes after the effect of latency hiding techniques are realized. The instruction-level model and its extensions model on-chip performance analytically giving insight into inherent performance bottlenecks in superscalar architectures. The statistical model and its hybrid extension provide other methods of categorizing codes via their statistical variations. The PTERA performance tool automates the use of performance counters for use by these methods across platforms making the modeling process easier still. These unique methods provide alternatives to performance modeling and categorizing not available previously in an attempt to utilize the inherent modeling capabilities of performance monitors on commodity processors for scientific applications
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